Surface protection of lithium metal anode

ABSTRACT

A method and apparatus for forming metal electrode structures, more specifically lithium-containing anodes, high performance electrochemical devices, such as primary and secondary electrochemical devices, including the aforementioned lithium-containing electrodes. In one implementation, the method comprises forming a lithium metal film on a current collector. The current collector comprises copper and/or stainless steel. The method further comprises forming a protective film stack on the lithium metal film, comprising forming a first protective film on the lithium metal film. The first protective film is selected from a bismuth chalcogenide film, a copper chalcogenide film, a tin chalcogenide film, a gallium chalcogenide film, a germanium chalcogenide film, an indium chalcogenide film, a silver chalcogenide film, a dielectric film, a lithium fluoride film, or a combination thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/658,286, filed on Oct. 21, 2019, which claims benefit of U.S.provisional patent application Ser. No. 62/839,117, filed Apr. 26, 2019,each of which are incorporated herein by reference in their entireties.

BACKGROUND Field

Implementations described herein generally relate to metal electrodes,more specifically lithium-containing anodes, high performanceelectrochemical devices, such as primary and secondary electrochemicaldevices, including the aforementioned lithium-containing electrodes, andmethods for fabricating the same.

Description of the Related Art

Rechargeable electrochemical storage systems are currently becomingincreasingly valuable for many fields of everyday life. High-capacityelectrochemical energy storage devices, such as lithium-ion (Li-ion)batteries, are used in a growing number of applications, includingportable electronics, medical, transportation, grid-connected largeenergy storage, renewable energy storage, and uninterruptible powersupply (UPS). Traditional lead/sulfuric acid batteries often lack thecapacitance and are often inadequately cyclable for these growingapplications. Both lithium-ion and subsequently, solid-state batteries,are thought to provide the best options for meeting increasingperformance demands.

Lithium provides an exceptional anode material for both lithium-ion andsolid-state batteries. Lithium is a light alkali metal with a highvoltage and theoretical capacity. However, like the heavy elementhomologs of the first main group, lithium is characterized by a strongreactivity with a variety of substances. Lithium reacts violently withwater, alcohols and other substances that contain protic hydrogen, oftenresulting in ignition. Lithium is unstable in air and reacts withoxygen, nitrogen and carbon dioxide. Lithium is normally handled underan inert gas atmosphere (noble gases such as argon) and the strongreactivity of lithium necessitates that other processing operations alsobe performed in an inert gas atmosphere. As a result, lithium providesseveral challenges when it comes to processing, storage, andtransportation.

Protective surface treatments have been developed for lithium metal. Onemethod of protective surface treatment of lithium metal includes coatingthe lithium metal with a wax layer, for example, polyethylene wax.However, a large amount of coating agent is typically applied whichinterferes with subsequent processing of the lithium metal film.

Another method of protective surface treatment proposes producingstabilized lithium metal powder (“SLMP”) with a continuous carbonatecoating, polymer coating, for example, polyurethanes, PTFE, PVC,polystyrene and others. However, these polymer coatings can causeproblems when prelithiating electrode materials.

Therefore, there is a need for methods and systems for the depositionand processing of lithium metals in energy storage systems.

SUMMARY

Implementations described herein generally relate to metal electrodes,more specifically lithium-containing anodes, high performanceelectrochemical devices, such as primary and secondary electrochemicaldevices, including the aforementioned lithium-containing electrodes, andmethods for fabricating the same. In one implementation, a method isprovided. The method comprises forming a lithium metal film on a currentcollector. The current collector comprises copper and/or stainlesssteel. The method further comprises forming a protective film stack onthe lithium metal film, comprising forming a first protective film onthe lithium metal film. The first protective film is selected from abismuth chalcogenide film, a copper chalcogenide film, a tinchalcogenide film, a gallium chalcogenide film, a germanium chalcogenidefilm, an indium chalcogenide film, a silver chalcogenide film, adielectric film, a lithium fluoride film, or a combination thereof.

In another implementation, an anode electrode structure is provided. Theanode electrode structure comprises a current collector comprisingcopper and/or stainless steel, a lithium metal film formed on thecurrent collector, and a protective film stack formed on the lithiummetal film. The protective film stack comprises a first protective filmformed on the lithium metal film. The first protective film is selectedfrom a bismuth chalcogenide film, a copper chalcogenide film, a tinchalcogenide film, a gallium chalcogenide film, a germanium chalcogenidefilm, an indium chalcogenide film, a silver chalcogenide film, adielectric film, a lithium fluoride film, or a combination thereof. Theprotective film stack further comprises a second protective film formedon the first protective film. The second protective film is selectedfrom a lithium fluoride (LiF) film, a metallic film, a carbon-containingfilm, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description ofthe implementations, briefly summarized above, may be had by referenceto implementations, some of which are illustrated in the appendeddrawings. It is to be noted, however, that the appended drawingsillustrate only typical implementations of this disclosure and aretherefore not to be considered limiting of its scope, for the disclosuremay admit to other equally effective implementations.

FIG. 1 illustrates a schematic cross-sectional view of oneimplementation of an energy storage device incorporating an electrodestructure formed according to one or more implementations describedherein;

FIG. 2 illustrates a cross-sectional view of one implementation of adual-sided anode electrode structure formed according to one or moreimplementations described herein;

FIG. 3 illustrates a cross-sectional view of one implementation of adual-sided anode electrode structure formed according to one or moreimplementations described herein;

FIG. 4 illustrates a process flow chart summarizing one implementationof a method for forming an anode electrode structure according to one ormore implementations described herein;

FIG. 5 illustrates a process flow chart summarizing one implementationof a method for forming an anode electrode structure according to one ormore implementations described herein; and

FIG. 6 illustrates a schematic view of an integrated processing tool forforming anode electrode structures according to one or moreimplementations described herein.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneimplementation may be beneficially incorporated in other implementationswithout further recitation.

DETAILED DESCRIPTION

The following disclosure describes anode electrodes, high performanceelectrochemical cells and batteries including the aforementioned anodeelectrodes, and methods for fabricating the same. Certain details areset forth in the following description and in FIGS. 1-6 to provide athorough understanding of various implementations of the disclosure.Other details describing well-known structures and systems oftenassociated with electrochemical cells and batteries are not set forth inthe following disclosure to avoid unnecessarily obscuring thedescription of the various implementations.

Many of the details, dimensions, angles and other features shown in theFigures are merely illustrative of particular implementations.Accordingly, other implementations can have other details, components,dimensions, angles and features without departing from the spirit orscope of the present disclosure. In addition, further implementations ofthe disclosure can be practiced without several of the details describedbelow.

Implementations described herein will be described below in reference toa reel-to-reel coating system, such as TopMet™, SMARTWEB®, TopBeam™, allof which are available from Applied Materials, Inc. of Santa Clara,Calif. Other tools capable of performing vapor deposition processes(e.g., physical vapor deposition (PVD) processes, chemical vapordeposition (CVD) processes, atomic layer deposition (ALD) processes) mayalso be adapted to benefit from the implementations described herein. Inaddition, any system enabling the vapor deposition processes describedherein can be used to advantage. The apparatus description describedherein is illustrative and should not be construed or interpreted aslimiting the scope of the implementations described herein. It shouldalso be understood that although described as a reel-to-reel process,the implementations described herein may also be performed on discretesubstrates. In some implementations, the reel-to-reel coating systemscan be combined to form device stack.

As described herein, flexible substrates can be considered to includeamong other things, films, foils, webs, strips of plastic material,metal, paper, or other materials. Typically, the terms “web,” “foil,”“strip,” “substrate” and the like are used synonymously.

Energy storage devices, for example, Li-ion batteries, typically includea positive electrode (e.g., cathode), and a negative electrode separatedby a polymer separator with a liquid electrolyte. Solid-state batteriesalso typically include a positive electrode (e.g., cathode) and anegative electrode (e.g., anode) but replace both the polymer separatorand the liquid electrolyte with an ion-conducting material.

Graphite anodes are the current state of the art but the industry ismoving from the graphite based anode to silicon blended graphite anodesto increase cell energy density. However, silicon blended graphiteanodes often suffer from irreversible capacity loss that occurs duringthe first cycle. Thus, there is a need for methods for replenishing thisfirst cycle capacity loss. The current generation of batteries usesgraphite anodes, a porous polymer separator, and a liquid electrolyte.The liquid electrolyte typically includes additives, which form a solidelectrolyte interface (SEI) in-situ during formation on the electrode.The SEI helps determine cycle life of the battery. The energy density ofthe state of the art graphite anode based battery is limited to around650 Wh/l. The energy density of a silicon powder blended graphite anodewill help boost the energy density to greater than 700 Wh/l. There is aneed for manufacturing technology to compensate for first cycleirreversible capacity loss of lithium associated with silicon anodes.Thus, the ability to use lithium in next generation batteries includingboth Li-ion batteries and solid-state batteries becomes increasinglysubstantial. However, lithium technology presents significant deviceintegration challenges such as handling lithium in dry room ambient,suitable surface protection technology, and the need to suppress oreliminate lithium metal dendrite during battery cycling. From theelectrochemical device perspective, an interface material, which notonly helps to prevent surface from oxidation but also should help inimproving device performance is desirable.

Using the implementations described herein, the deposited lithium metal,either single-sided or dual-sided, can be protected during winding andunwinding of the reels downstream. Deposition of one or more thinprotective films as described herein has several advantages. In someimplementations, the one or more protective films described hereinprovide adequate surface protection for shipping, handling, and storageas well as avoiding surface reactions of lithium during deviceintegration. In some implementations, the one or more protective filmsdescribed herein are compatible with lithium ions and reduce impedancefor ions to move across. In some implementations, the one or moreprotective films described herein are ion-conducting and thus may beincorporated into the formed energy storage device. In someimplementations, the one or more protective films described herein canalso help suppress or eliminate lithium dendrites, especially at highcurrent density operation. In some implementations, the use ofprotective films described herein reduces the complexity ofmanufacturing systems and is compatible with current manufacturingsystems.

FIG. 1 illustrates a schematic cross-sectional view of oneimplementation of an energy storage device 100 incorporating an anodeelectrode structure formed according to implementations describedherein. The energy storage device 100 may be a solid-state energystorage device or a lithium-ion based energy storage device. The energystorage device 100, even though shown as a planar structure, may also beformed into a cylinder by rolling the stack of layers; furthermore,other cell configurations (e.g., prismatic cells, button cells, orstacked electrode cells) may be formed. The energy storage device 100includes an anode electrode structure 110 and a cathode electrodestructure 120 with a solid-electrolyte film 130 positioned therebetween.In implementations where the energy storage device 100 is a Li-ionenergy storage device, the solid-electrolyte film is replaced with apolymer separator and a liquid electrolyte. The cathode electrodestructure 120 includes a cathode current collector 140 and a cathodefilm 150. The anode electrode structure 110 includes an anode currentcollector 160, an anode film 170, and one or more protective film(s)180. The one or more protective film(s) 180 include at least one or moreof a lithium fluoride (LiF) film; a dielectric or ceramic film (e.g.,oxides of titanium (Ti), aluminum (Al), niobium (Nb), tantalum (Ta),zirconium (Zr), or a combination thereof); one or more metal film(s)(e.g., tin (Sn), antimony (Sb), bismuth (Bi), gallium (Ga), germanium(Ge), copper films, silver films, gold films, or a combination thereof);a copper chalcogenide film (e.g., CuS, Cu₂Se, Cu₂S); a bismuthchalcogenide film (e.g., Bi₂Te₃, Bi₂Se₃); a tin chalcogenide film (e.g.,SnTe, SnSe, SnSe₂, SnS), a gallium chalcogenide film (e.g., GaS, Ga₂S₃,GaSe, Ga₂Se₃, GaTe), a germanium chalcogenide film (GeTe, GeSe, GeS), anindium chalcogenide film (e.g., InS, In₆S₇, In₂S₃, InSe, InS₄Se₃,In₆Se₇, In₂Se₃, InTe, In₄Te₃, In₃Te₄, In₇Te₁₀, In₂Te₃, In₂Te₅), a silverchalcogenide film (Ag₂Se, Ag₂S, Ag₂Te), boron nitride, lithium nitrate,lithium borohydride, and a combination thereof; and a carbon-containingfilm.

The cathode electrode structure 120 includes the cathode currentcollector 140 with the cathode film 150 formed on the cathode currentcollector 140. It should be understood that the cathode electrodestructure 120 may include other elements or films.

The current collectors 140, 160, on the cathode film 150 and the anodefilm 170, respectively, can be identical or different electronicconductors. In some implementations, at least one of the currentcollectors 140, 160 is a flexible substrate. In some implementations,the flexible substrate is a CPP film (i.e., a casting polypropylenefilm), an OPP film (i.e., an oriented polypropylene film), or a PET film(i.e., an oriented polyethylene terephthalate film). Alternatively, theflexible substrate may be a pre-coated paper, a polypropylene (PP) film,a PEN film, a poly lactase acetate (PLA) film, or a PVC film. Examplesof metals that the current collectors 140, 160 may be comprised ofinclude aluminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co),manganese (Mn), chromium (Cr), stainless steel, clad materials, alloysthereof, and a combination thereof. In one implementation, at least oneof the current collectors 140, 160 is perforated. In one implementation,at least one of the current collectors 140, 160 includes a polymersubstrate (e.g., polyethylene terephthalate (“PET”) coated with ametallic material. In one implementation, the anode current collector160 is a polymer substrate (e.g., a PET film) coated with copper. Inanother implementation, the anode current collector 160 is a multi-metallayer on a polymer substrate. The multi-metal layer can be combinationsof copper, chromium, nickel, etc. In one implementation, the anodecurrent collector 160 is a multi-layer structure that includes acopper-nickel cladding material. In one implementation, the multi-layerstructure includes a first layer of nickel or chromium, a second layerof copper formed on the first layer, and a third layer including nickel,chromium, or both formed on the second layer. In one implementation, theanode current collector 160 is nickel coated copper. Furthermore,current collectors may be of any form factor (e.g., metallic foil,sheet, or plate), shape and micro/macro structure.

Generally, in prismatic cells, tabs are formed of the same material asthe current collector and may be formed during fabrication of the stack,or added later. In some implementations, the current collectors extendbeyond the stack and the portions of the current collector extendingbeyond the stack may be used as tabs. In one implementation, the cathodecurrent collector 140 is aluminum. In another implementation, thecathode current collector 140 comprises aluminum deposited on a polymersubstrate (e.g., a PET film). In one implementation, the cathode currentcollector 140 has a thickness below 50 μm more specifically, 5 μm or,even more specifically 2 μm. In one implementation, the cathode currentcollector 140 has a thickness from about 0.5 μm to about 20 μm (e.g.,from about 1 μm to about 10 μm; from about 2 μm to about 8 μm; or fromabout 5 μm to about 10 μm). In one implementation, the anode currentcollector 160 is copper. In one implementation, the anode currentcollector 160 is stainless steel. In one implementation, the anodecurrent collector 160 has a thickness below 50 μm more specifically, 5μm or, even more specifically 2 μm. In one implementation, the anodecurrent collector 160 has a thickness from about 0.5 μm to about 20 μm(e.g., from about 1 μm to about 10 μm; from about 2 μm to about 8 μm;from about 6 μm to about 12 μm; or from about 5 μm to about 10 μm).

The cathode film 150 or cathode may be any material compatible with theanode and may include an intercalation compound, an insertion compound,or an electrochemically active polymer. Suitable intercalation materialsinclude, for example, lithium-containing metal oxides, MoS₂, FeS₂, BiF₃,Fe₂OF₄, MnO₂, TiS₂, NbSe₃, LiCoO₂, LiNiO₂, LiMnO₂, LiMn₂O₄, V₆O₁₃ andV₂O₅. Suitable polymers include, for example, polyacetylene,polypyrrole, polyaniline, and polythiophene. The cathode film 150 orcathode may be made from a layered oxide, such as lithium cobalt oxide,an olivine, such as lithium iron phosphate, or a spinel, such as lithiummanganese oxide. Exemplary lithium-containing oxides may be layered,such as lithium cobalt oxide (LiCoO₂), or mixed metal oxides, such asLiNi_(x)Co_(1-2x)MnO₂, LiNiMnCoO₂ (“NMC”), LiNi_(0.5)Mn_(1.5)O₄,Li(Ni_(0.8)Co_(0.15)Al_(0.05))O₂, LiMn₂O₄, and doped lithium richlayered-layered materials, wherein x is zero or a non-zero number.Exemplary phosphates may be iron olivine (LiFePO₄) and it is variants(such as LiFe_((1-x))Mg_(x)PO₄), LiMoPO₄, LiCoPO₄, LiNiPO₄, Li₃V₂(PO₄)₃,LiVOPO₄, LiMP₂O₇, or LiFe_(1.5)P₂O₇, wherein x is zero or a non-zeronumber. Exemplary fluorophosphates may be LiVPO₄F, LiAlPO₄F,Li₅V(PO₄)₂F₂, Li₅Cr(PO₄)₂F₂, Li₂CoPO₄F, or Li₂NiPO₄F. Exemplarysilicates may be Li₂FeSiO₄, Li₂MnSiO₄, or Li₂VOSiO₄. An exemplarynon-lithium compound is Na₅V₂(PO₄)₂F₃.

The anode electrode structure 110 includes the anode current collector160 with the anode film 170 formed on the anode current collector 160.The anode electrode structure 110 comprises the one or more protectivefilm(s) 180, which includes at least one or more of a lithium fluoride(LiF) film; a dielectric or ceramic film (e.g., oxides of titanium (Ti),aluminum (Al), niobium (Nb), tantalum (Ta), zirconium (Zr), or acombination thereof); one or more metal film(s) (e.g., tin (Sn),antimony (Sb), bismuth (Bi), gallium (Ga), germanium (Ge), copper films,silver films, gold films, or a combination thereof); a copperchalcogenide film (e.g., CuS, Cu₂Se, Cu₂S); a bismuth chalcogenide film(e.g., Bi₂Te₃, Bi₂Se₃); a tin chalcogenide film (e.g., SnTe, SnSe,SnSe₂, SnS), a gallium chalcogenide film (e.g., GaS, Ga₂S₃, GaSe,Ga₂Se₃, GaTe), a germanium chalcogenide film (GeTe, GeSe, GeS), anindium chalcogenide film (e.g., InS, In₆S₇, In₂S₃, InSe, InS₄Se₃,In₆Se₇, In₂Se₃, InTe, In₄Te₃, In₃Te₄, In₇Te₁₀, In₂Te₃, In₂Te₅), a silverchalcogenide film (Ag₂Se, Ag₂S, Ag₂Te), boron nitride, lithium nitrate,lithium borohydride, and a combination thereof; and a carbon-containingfilm. In some implementations, the one or more protective film(s) areion-conducting films.

The anode film 170 may be any material compatible with the cathode film150. The anode film 170 may have an energy capacity greater than orequal to 372 mAh/g, preferably 700 mAh/g, and most preferably 1000mAh/g. The anode film 170 may be constructed from graphite,silicon-containing graphite, lithium metal, lithium metal foil or alithium alloy foil (e.g. lithium aluminum alloys), or a mixture of alithium metal and/or lithium alloy and materials such as carbon (e.g.coke, graphite), nickel, copper, tin, indium, silicon, oxides thereof,or a combination thereof. The anode film 170 typically comprisesintercalation compounds containing lithium or insertion compoundscontaining lithium. In some implementations, the anode film is a lithiummetal film. In some implementations, wherein the anode film 170comprises lithium metal, the lithium metal may be deposited using themethods described herein.

In one implementation, the anode film 170 has a thickness from about 10μm to about 200 μm (e.g., from about 1 μm to about 100 μm; from about 10μm to about 30 μm; from about 20 μm to about 30 μm; from about 1 μm toabout 20 μm; or from about 50 μm to about 100 μm).

In some implementations, the one or more protective film(s) 180 isformed on the anode film 170. The one or more protective film(s) 180includes at least one or more of a lithium fluoride (LiF) film; adielectric or ceramic film (e.g., oxides of titanium (Ti), aluminum(Al), niobium (Nb), tantalum (Ta), zirconium (Zr), or a combinationthereof); one or more metal film(s) (e.g., tin (Sn), antimony (Sb),bismuth (Bi), gallium (Ga), germanium (Ge), copper films, silver films,gold films, or a combination thereof); a copper chalcogenide film (e.g.,CuS, Cu₂Se, Cu₂S); a bismuth chalcogenide film (e.g., Bi₂Te₃, Bi₂Se₃); atin chalcogenide film (e.g., SnTe, SnSe, SnSe₂, SnS), a galliumchalcogenide film (e.g., GaS, Ga₂S₃, GaSe, Ga₂Se₃, GaTe), a germaniumchalcogenide film (GeTe, GeSe, GeS), an indium chalcogenide film (e.g.,InS, In₆S₇, In₂S₃, InSe, InS₄Se₃, In₆Se₇, In₂Se₃, InTe, In₄Te₃, In₃Te₄,In₇Te₁₀, In₂Te₃, In₂Te₅), a silver chalcogenide film (Ag₂Se, Ag₂S,Ag₂Te), boron nitride, lithium nitrate, lithium borohydride, and acombination thereof; and a carbon-containing film. In someimplementations, the one or more protective film(s) are ion-conductingfilms. In some implementations, the one or more protective film(s) 180are permeable to at least one of lithium ions and lithium atoms. The oneor more protective film(s) 180 provide surface protection of the anodefilm 170, which allows for handling of the anode film in a dry room. Insome implementations where the energy storage device 100 is asolid-state energy storage device, the one or more protective film(s)180 contribute to the formation of an improved SEI layer and thusimprove device performance. The one or more protective film(s) 180 canbe directly deposited on the anode film 170 by Physical Vapor Deposition(PVD), such as evaporation (e.g., thermal or e-beam) or sputtering,atomic layer deposition (ALD), a slot-die process, dip coating, planarflow melt-spin process, a thin-film transfer process, gravure coating ora three-dimensional lithium printing process.

In some implementations, the one or more protective film(s) 180 includea lithium fluoride (LiF) film.

In some implementations, the one or more protective film(s) 180 includeone or more dielectric film(s). In some implementations, the dielectricfilm is a ceramic film. In some implementations, the dielectric film isan ion-conducting ceramic film. Suitable dielectric film(s) include butare not limited to titanium oxides (e.g., TiO₂), aluminum oxides (e.g.,Al₂O₃, AlO_(x), AlO_(x)NO_(y)), boron nitride, aluminum oxyhydroxideAlO(OH), niobium oxides (e.g., NbO, NbO₂, Nb₂O₅), tantalum oxides (e.g.,Ta₂O₅), zirconium oxides (ZrO₂), or a combination thereof. In someimplementations, the dielectric film is a binder-free ceramic coating.In some implementations, the dielectric film is a porous aluminum oxidefilm.

In some implementations, the one or more protective film(s) 180 includeone or more metal film(s). Suitable metal film(s) include but are notlimited to tin films, antimony films, bismuth films, gallium films,germanium films, copper, silver, gold, or a combination thereof. The oneor more metal film(s) may be an ultra-thin metal seed film.

In some implementations, the one or more protective film(s) 180 includeone or more metal chalcogenide film(s). Suitable chalcogenide filmsinclude but are not limited to copper chalcogenides (e.g., CuS, Cu₂Se,Cu₂S) and bismuth chalcogenides (e.g., Bi₂Te₃, Bi₂Se₃), tinchalcogenides (e.g., SnTe, SnSe, SnSe₂, SnS), gallium chalcogenides(e.g., GaS, Ga₂S₃, GaSe, Ga₂Se₃, GaTe), germanium chalcogenides (GeTe,GeSe, GeS), indium chalcogenides (e.g., InS, In₆S₇, In₂S₃, InSe,InS₄Se₃, In₆Se₇, In₂Se₃, InTe, In₄Te₃, In₃Te₄, In₇Te₁₀, In₂Te₃, In₂Te₅),silver chalcogenides (Ag₂Se, Ag₂S, Ag₂Te), boron nitride, lithiumnitrate, lithium borohydride, and a combination thereof.

In some implementations, the one or more protective film(s) 180 includecarbon-containing films. Suitable carbon-containing films include butare not limited to amorphous carbon films (e.g., diamond-like carbon(DLC)), CVD diamond films, graphite films, and graphene oxides.

In some implementations, each layer of the one or more protectivefilm(s) 180 is a coating or a discrete film having a thickness in arange of 1 nanometer to 3,000 nanometers (e.g., in the range of 10nanometers to 600 nanometers; in the range of 50 nanometers to 100nanometers; in the range of 50 nanometers to 200 nanometers; in therange of 100 nanometers to 150 nanometers). In some implementations,each layer of the one or more protective film(s) 180 is a coating ordiscrete film having a thickness of 500 nanometers or less (e.g., fromabout 1 nm to about 400 nm; from about 25 nm to about 300 nm; from about50 nm to about 200 nm; from about 100 nm to about 150 nm; from about 10nm to about 80 nm; or from about 30 to about 60 nanometers). In someimplementations, each layer of the one or more protective film(s) 180 isa coating or discrete film having a thickness of 100 nanometers or less(e.g., from about 5 nanometers to about 100 nanometers; from about 5nanometers to about 40 nanometers; from about 10 nanometers to about 20nanometers; or from about 50 nanometers to about 100 nanometers).

In some implementations, at least one of the one or more protectivefilm(s) 180 is porous. In some implementations, at least one of the oneor more protective film(s) 180 has nanopores. In some implementations,at least one of the one or more protective film(s) 180 has a pluralityof nanopores that are sized to have an average pore size or diameterless than about 10 nanometers (e.g., from about 1 nanometer to about 10nanometers; from about 3 nanometers to about 5 nanometers). In anotherimplementation, at least one of the one or more protective film(s) 180has a plurality of nanopores sized to have an average pore size ordiameter less than about 5 nanometers. In one implementation, at leastone of the one or more protective film(s) 180 has a plurality ofnanopores having a diameter ranging from about 1 nanometer to about 20nanometers (e.g., from about 2 nanometers to about 15 nanometers; orfrom about 5 nanometers to about 10 nanometers).

In some implementations, the solid-electrolyte film 130 is a lithium-ionconducting material. In some implementations, the lithium-ion conductingmaterial is a lithium-ion conducting ceramic or a lithium-ion conductingglass. The Li-ion conducting material may be comprised of one or more ofLiPON, doped variants of either crystalline or amorphous phases ofLi₇La₃Zr₂O₁₂, doped anti-perovskite compositions, argyroditecompositions (e.g., Li₆PS₅Br, Li₆PS₅Cl, Li₇PS₆, Li₃SBF₄,A_(3-2×0.005)Ba_(0.005)OCI (A=alkali metal),Li_(9.54)Si_(1.74)P_(1.44)S_(11.7)Cl_(0.3), Li₆PS₅I, Li₆PO₅Cl),lithium-sulfur-phosphorous materials, (Li_(0.7)Na_(0.3))₃BH₄B₁₂H₁₂,Li₂S—P₂S₅, Li₁₀GeP₂S₁₂, and Li₃PS₄, lithium phosphate glasses,(1-x)LiI-(x)Li₄SnS₄, xLiI-(1-x)Li₄SnS₄, mixed sulfide and oxideelectrolytes (crystalline LLZO, amorphous (1-x)LiI-(x)Li₄SnS₄ mixture,amorphous xLiI-(1-x)Li₄SnS₄), Li₃S(BF₄)_(0.5)Cl_(0.5), Li₄Ti₅O₁₂,lithium doped lanthanum titanate (LATP), Li_(2+2x)Zn_(1-x)GeO₄,LiM₂(PO₄)₃ where M=Ti, Ge, Hf, for example. In one implementation, x isbetween 0 and 1 (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9).

FIG. 2 illustrates a cross-sectional view of one implementation of ananode electrode structure 200 formed according to implementationsdescribed herein. Note in FIG. 2 that the anode current collector 160 isshown to extend beyond the stack, although it is not necessary for theanode current collector 160 to extend beyond the stack, the portionsextending beyond the stack may be used as tabs. Although the anodeelectrode structure 200 is depicted as a dual-sided electrode structure,it should be understood that the implementations described herein alsoapply to single-sided electrode structures.

The anode electrode structure 200 has the anode current collector 160,anode films 170 a, 170 b (collectively 170) formed on opposing sides ofthe anode current collector 160. In one implementation, the anode film170 is a lithium metal film. In one implementation, the anode film 170has a thickness of 20 micrometers or less (e.g., from about 1 micrometerto about 20 micrometer). A first protective film 210 a, 210 b(collectively 210) is formed on each of the anode films 170 a, 170 b. Inone implementation, the first protective film 210 is selected from thegroup comprising a metal chalcogenide film, a dielectric film, ametallic film, a lithium fluoride film, or a combination thereof. Insome implementations, the first protective film 210 has a thickness in arange of 1 nanometer to 3,000 nanometers (e.g., in the range of 10nanometers to 600 nanometers; in the range of 50 nanometers to 100nanometers; in the range of 50 nanometers to 200 nanometers; in therange of 100 nanometers to 150 nanometers). In some implementations, thefirst protective film 210 has a thickness of 100 nanometers or less(e.g., from about 5 nanometers to 100 nanometers; from about 5nanometers to about 40 nanometers; from about 10 nanometers to about 20nanometers; or from about 50 nanometers to about 100 nanometers). Insome implementations, as depicted in FIG. 2 , the first protective film210 coats the exposed surfaces (e.g., top surface and sidewalls) of theanode film 170 extending to contact the anode current collector 160.

A second protective film 220 a, 220 b (collectively 220) is formed oneach on the first protective film(s) 210. In some implementations, thesecond protective film 220 is permeable to at least one of lithium ionsand lithium atoms. In one implementation, the second protective film 220is selected from the group comprising lithium fluoride films, metallicfilms, carbon-containing films, or a combination thereof. In someimplementations, the second protective film 220 has a thickness in arange of 1 nanometer to 3,000 nanometers (e.g., in the range of 10nanometers to 600 nanometers; in the range of 50 nanometers to 100nanometers; in the range of 50 nanometers to 200 nanometers; in therange of 100 nanometers to 150 nanometers). In some implementations, thesecond protective film 220 has a thickness of 100 nanometers or less(e.g., from about 5 nanometers to 100 nanometers; from about 5nanometers to about 40 nanometers; from about 10 nanometers to about 20nanometers; or from about 50 nanometers to about 100 nanometers).

In some implementations, the first protective film 210 is a metalchalcogenide film and the second protective film 220 is a lithiumfluoride film. In some implementations, the first protective film 210 isa dielectric film and the second protective film 220 is a lithiumfluoride film. In some implementations, the first protective film 210 isa metal chalcogenide film and the second protective film 220 is ametallic film. In some implementations, the first protective film 210 isa metallic film and the second protective film 220 is a lithium fluoridefilm. In some implementations, the first protective film 210 is a LiFfilm and the second protective film 220 is carbon or graphene oxide.

FIG. 3 illustrates a cross-sectional view of one implementation of ananode electrode structure 300 formed according to implementationsdescribed herein. Note in FIG. 3 that the anode current collector 160 isshown to extend beyond the stack, although it is not necessary for theanode current collector 160 to extend beyond the stack, the portionsextending beyond the stack may be used as tabs. Although the anodeelectrode structure 300 is depicted as a dual-sided electrode structure,it should be understood that the implementations described herein alsoapply to single-sided electrode structures.

The anode electrode structure 300 has the anode current collector 160,anode films 170 a, 170 b (collectively 170) formed on opposing sides ofthe anode current collector 160. In one implementation, the anode film170 is a lithium metal film. In one implementation, the anode film 170has a thickness of 20 micrometers or less (e.g., from about 1 micrometerto about 20 micrometer). A carbon-containing protective film 310 a, 310b (collectively 310) is formed on each of the anode films 170 a, 170 b.In one implementation, the carbon-containing protective film 310 isselected from the group comprising amorphous carbon films (e.g.,diamond-like carbon (DLC)), CVD diamond films, graphite films, andgraphene oxides. In some implementations, the carbon protective film 310has a thickness of 500 nanometers or less (e.g., from about 1 nm toabout 400 nm; from about 25 nm to about 300 nm; from about 50 nm toabout 200 nm; from about 100 nm to about 150 nm; from about 10 nm toabout 80 nm; or from about 30 to about 60 nanometers). In someimplementation, the carbon protective film 310 has a thickness of 100nanometers or less (e.g., from about 5 nanometers to 100 nanometers;from about 5 nanometers to about 40 nanometers; from about 10 nanometersto about 20 nanometers; or from about 50 nanometers to about 100nanometers). In some implementations, as depicted in FIG. 3 , thecarbon-containing protective film 310 coats the exposed surfaces (e.g.,top surface and sidewalls) of the anode film 170 extending to contactthe anode current collector 160.

FIG. 4 illustrates a process flow chart summarizing one implementationof a method 400 for forming an anode electrode structure according toimplementations described herein. The anode electrode structure may bethe anode electrode structure 200 depicted in FIG. 2 . At operation 410,a substrate is provided. In one implementation, the substrate is acontinuous sheet of material 650 as shown in FIG. 6 . In oneimplementation, the substrate is the anode current collector 160.Examples of metals that the substrate may be comprised of includealuminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co),manganese (Mn), chromium (Cr), stainless steel, clad materials, alloysthereof, and a combination thereof. In one implementation, the substrateis copper material. In one implementation, the substrate is a stainlesssteel material. In one implementation, the substrate is perforated.Furthermore, the substrate may be of any form factor (e.g., metallicfoil, sheet, or plate), shape and micro/macro structure.

In some implementations, the substrate is exposed to a pretreatmentprocess, which includes at least one of a plasma treatment or coronadischarge process to remove organic materials from the exposed surfacesof the current collector. The pretreatment process is performed prior tofilm deposition on the substrate.

At operation 420, a lithium metal film is formed on the substrate. Inone implementation, the lithium metal film is the anode film 170 and thesubstrate is the anode current collector 160. In one implementation, thelithium metal film is formed on a copper current collector. In someimplementations, if an anode film is already present on the substrate,the lithium metal film is formed on the anode film. If the anode film170 is not present, the lithium metal film may be formed directly on thesubstrate. Any suitable lithium metal film deposition process fordepositing thin films of lithium metal may be used to deposit the thinfilm of lithium metal. Deposition of the thin film of lithium metal maybe by PVD processes, such as evaporation (e.g., thermal evaporation ore-beam), a slot-die process, a transfer process, or a three-dimensionallithium printing process. The chamber for depositing the thin film oflithium metal may include a PVD system, such as an electron-beamevaporator, a thermal evaporator, or a sputtering system, a thin filmtransfer system (including large area pattern printing systems such asgravure printing systems) or a slot-die deposition system.

At operation 430, a first protective film is formed on the lithium metalfilm. With reference to FIG. 2 , the first protective film may be thefirst protective film 210 and the lithium metal film may be anode film170. In one implementation, the first protective film 210 is selectedfrom the group comprising a metal chalcogenide film, a dielectric film,a metallic film, a lithium fluoride film, or a combination thereof. Insome implementations, the first protective film 210 has a thickness in arange of 1 nanometer to 3,000 nanometers (e.g., in the range of 10nanometers to 600 nanometers; in the range of 50 nanometers to 100nanometers; in the range of 50 nanometers to 200 nanometers; in therange of 100 nanometers to 150 nanometers). In some implementations, thefirst protective film 210 has a thickness of 500 nanometers or less(e.g., from about 1 nm to about 400 nm; from about 25 nm to about 300nm; from about 50 nm to about 200 nm; from about 100 nm to about 150 nm;from about 10 nm to about 80 nm; or from about 30 to about 60nanometers). In some implementations, the first protective film 210 hasa thickness of 100 nanometers or less (e.g., from about 5 nanometers to100 nanometers; from about 10 nanometers to about 20 nanometers; or fromabout 50 nanometers to about 100 nanometers).

In some implementations, the first protective film 210 is a metalchalcogenide film. In some implementations, the metal chalcogenide filmis deposited using a PVD process having an RF power source coupled to atarget. The target is typically composed of the materials of the metalchalcogenide film. For example, in one implementation, the target is abismuth-telluride alloy target. In one implementation, thebismuth-telluride alloy target comprises from about 5 at. % to about 95at. % bismuth and from about 5 at. % to about 95 at. % tellurium. Theplasma may be generated from a non-reactive gas such as argon (Ar),krypton (Kr), nitrogen, etc. For example, a plasma may be generated fromargon gas having a flow rate within a range from about 30 standard cubiccentimeters (sccm) to about 200 sccm, such as about 100 sccm to about150 sccm. An RF power may be applied to the target at a power levelwithin a range from about 50 W to about 4,000 W, for example, about 1000W to about 3000 W, such as about 2000 W. The deposition chamber may bepressurized from about 0.1 mTorr to about 500 mTorr. The depositionchamber may be pressurized from about 0.1 mTorr to about 100 mTorr, forexample, from about 10 mTorr to about 30 mTorr, such as 25 mTorr. Thesubstrate may be electrically “floating” and have no bias. In oneimplementation, the deposition process of operation 430 may be performedat a deposition temperature from about 50° C. to about 400° C., forexample, from about 100° C. to about 200° C., such as about 120° C.

In another implementation, the plasma may be generated using a DC powersource coupled to bismuth-telluride alloy target. The substrate may beelectrically “floating” and have no bias. In this implementation, plasmamay be generated from an argon gas having a flow rate within a rangefrom about 30 standard cubic centimeters (sccm) to about 200 sccm, suchas about 100 sccm to about 150 sccm. A DC power may be applied to thetarget at a power level within a range from about 50 W to about 5,000 W,from about 1000 W to about 3000 W, for example between about 1000 W toabout 2000 W, such as about 2000 W. The deposition chamber may bepressurized from about 0.1 mTorr to about 500 mTorr. The depositionchamber may be pressurized from about 0.1 mTorr to about 500 mTorr. Thedeposition chamber may be pressurized from about 0.1 mTorr to about 100mTorr, for example, from about 10 mTorr to about 30 mTorr, such as 25mTorr. The substrate may be electrically “floating” and have no bias.The deposition process of operation 430 may be performed at a depositiontemperature from about 50° C. to about 400° C., for example, from about100° C. to about 200° C., such as about 120° C.

In some implementations, the first protective film 210 is a dielectric.Suitable methods for depositing the dielectric film include, but are notlimited to, PVD, such as evaporation or sputtering, a slot-die process,a thin-film transfer process, a chemical vapor deposition (CVD) process,or a three-dimensional lithium printing process.

In some implementations, the first protective film 210 is a metal film.In some implementations, the metal film is a copper film, a bismuthfilm, a tin film, a gallium film, or a germanium film. In someimplementations, the metal film is an ultra-thin metal film. Anysuitable metal film deposition process for depositing thin films ofmetal may be used to deposit the thin film of metal. Deposition of thethin film of metal may be by a PVD process, such as evaporation (e.g.,thermal or e-beam), a CVD process, a slot-die process, a transferprocess, or a three-dimensional lithium printing process. The chamberfor depositing the thin film of metal may include a PVD system, such asan electron-beam evaporator, a thermal evaporator, or a sputteringsystem, a thin film transfer system (including large area patternprinting systems such as gravure printing systems) or a slot-diedeposition system.

At operation 440, a second protective film is formed on the firstprotective film. With reference to FIG. 2 , the second protective filmmay be the second protective film 220 and the first protective film maybe the first protective film 210. In one implementation, the secondprotective film 220 is selected from the group comprising a lithiumfluoride film, a metal film, a carbon-containing film, or a combinationthereof. In some implementations, the second protective film 220 has athickness in a range of 1 nanometer to 3,000 nanometers (e.g., in therange of 10 nanometers to 600 nanometers; in the range of 50 nanometersto 100 nanometers; in the range of 50 nanometers to 200 nanometers; inthe range of 100 nanometers to 150 nanometers). In some implementations,the second protective film 220 has a thickness of 500 nanometers or less(e.g., from about 1 nm to about 400 nm; from about 25 nm to about 300nm; from about 50 nm to about 200 nm; from about 100 nm to about 150 nm;from about 10 nm to about 80 nm; or from about 30 to about 60nanometers). In some implementations, the second protective film 220 hasa thickness of 100 nanometers or less (e.g., from about 5 nanometers to100 nanometers; from about 10 nanometers to about 20 nanometers; or fromabout 50 nanometers to about 100 nanometers).

In some implementations, the second protective film 220 is a lithiumfluoride film. Suitable methods for depositing the lithium fluoride filminclude, but are not limited to, PVD, such as evaporation or sputtering,a slot-die process, a thin-film transfer process, a chemical vapordeposition (CVD) process, or a three-dimensional lithium printingprocess. In some implementations, PVD is the method for deposition ofthe lithium fluoride film. In some implementations, the lithium fluoridefilm is deposited using a thermal evaporation process. In someimplementations, the lithium fluoride film is deposited using an e-beamevaporation process.

In some implementations, the second protective film 220 is a metal film.In some implementations, the metal film is a copper film, a bismuthfilm, a tin film, a gallium film, or a germanium film. In someimplementations, the metal film is an ultra-thin metal film. Anysuitable metal film deposition process for depositing thin films ofmetal may be used to deposit the thin film of metal. Deposition of thethin film of metal may be by a PVD process, such as evaporation (e.g.,thermal or e-beam), a CVD process, a slot-die process, a transferprocess, or a three-dimensional lithium printing process. The chamberfor depositing the thin film of metal may include a PVD system, such asan electron-beam evaporator, a thermal evaporator, or a sputteringsystem, a thin film transfer system (including large area patternprinting systems such as gravure printing systems) or a slot-diedeposition system.

FIG. 5 illustrates a process flow chart summarizing one implementationof a method 500 for forming an anode electrode structure according toone or more implementations described herein. The anode electrodestructure may be the anode electrode structure 300 depicted in FIG. 3 .At operation 510, a substrate is provided. In one implementation, thesubstrate is a continuous sheet of material 650 as shown in FIG. 6 . Inone implementation, the substrate is the anode current collector 160.Examples of metals that the substrate may be comprised of includealuminum (Al), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co),manganese (Mn), chromium (Cr), stainless steel, clad materials, alloysthereof, and a combination thereof. In one implementation, the substrateis copper material. In one implementation, the substrate is stainlesssteel. In one implementation, the substrate is perforated. Furthermore,the substrate may be of any form factor (e.g., metallic foil, sheet, orplate), shape and micro/macro structure.

In some implementations, the substrate is exposed to a pretreatmentprocess, which includes at least one of a plasma treatment or coronadischarge process to remove organic materials from the exposed surfacesof the current collector. The pretreatment process is performed prior tofilm deposition on the substrate.

At operation 520, a lithium metal film is formed on the substrate. Inone implementation, the lithium metal film is the anode film 170 and thesubstrate is the anode current collector 160. In one implementation, thelithium metal film is formed on a copper current collector. In someimplementations, if an anode film is already present on the substrate,the lithium metal film is formed on the anode film. If the anode film170 is not present, the lithium metal film may be formed directly on thesubstrate. Any suitable lithium metal film deposition process fordepositing thin films of lithium metal may be used to deposit the thinfilm of lithium metal. Deposition of the thin film of lithium metal maybe by PVD processes, such as evaporation, a slot-die process, a transferprocess, or a three-dimensional lithium printing process. The chamberfor depositing the thin film of lithium metal may include a PVD system,such as an electron-beam evaporator, a thermal evaporator, or asputtering system, a thin film transfer system (including large areapattern printing systems such as gravure printing systems) or a slot-diedeposition system.

At operation 530, a carbon-containing protective film is formed on thelithium metal film. With reference to FIG. 3 , the carbon-containingprotective film may be the carbon-containing protective film 310 and thelithium metal film may be the anode film 170. In one implementation, thecarbon-containing protective film 310 is selected from the groupcomprising amorphous carbon films (e.g., diamond-like carbon (DLC)), CVDdiamond films, graphite films, and graphene oxides. In someimplementations, the carbon-containing protective film 310 has athickness of 500 nanometers or less (e.g., from about 1 nm to about 400nm; from about 25 nm to about 300 nm; from about 50 nm to about 200 nm;from about 100 nm to about 150 nm; from about 10 nm to about 80 nm; orfrom about 30 to about 60 nanometers). In one implementation, thecarbon-containing protective film 310 has a thickness of 100 nanometersor less (e.g., from about 5 nanometers to 100 nanometers; from about 10nanometers to about 20 nanometers; or from about 50 nanometers to about100 nanometers).

Any suitable carbon-containing film deposition process may be used todeposit the carbon-containing protective film. Deposition of thecarbon-containing film may be by PVD processes, such as evaporation(e.g., thermal or e-beam), a CVD process, a slot-die process, a transferprocess, or a three-dimensional lithium printing process. The chamberfor depositing the carbon-containing film may include a PVD system, suchas an electron-beam evaporator, a thermal evaporator, or a sputteringsystem, a thin film transfer system (including large area patternprinting systems such as gravure printing systems) or a slot-diedeposition system.

FIG. 6 illustrates a schematic view of a flexible substrate coatingapparatus 600 for forming anode electrode structures according toimplementations described herein. The flexible substrate coatingapparatus 600 may be a SMARTWEB®, manufactured by Applied Materials,adapted for manufacturing lithium anode devices according to theimplementations described herein. According to typical implementations,the flexible substrate coating apparatus 600 can be used formanufacturing lithium anodes, and particularly for SEI film stacks forlithium anodes. The flexible substrate coating apparatus 600 isconstituted as a roll-to-roll system including an unwinding module 602,a processing module 604 and a winding module 606. In someimplementations, the processing module 604 comprises a plurality ofprocessing modules or chambers 610, 620, 630 and 640 arranged insequence, each configured to perform one processing operation to thecontinuous sheet of material 650 or web of material. In oneimplementation, as depicted in FIG. 6 , the processing chambers 610-640are radially disposed about a coating drum 655. Arrangements other thanradial are contemplated. For example, in another implementation, theprocessing chambers may be positioned in a linear configuration.

In one implementation, the processing chambers 610-640 are stand-alonemodular processing chambers wherein each modular processing chamber isstructurally separated from the other modular processing chambers.Therefore, each of the stand-alone modular processing chambers, can bearranged, rearranged, replaced, or maintained independently withoutaffecting each other. Although four processing chambers 610-640 areshown, it should be understood that any number of processing chambersmay be included in the flexible substrate coating apparatus 600.

The processing chambers 610-640 may include any suitable structure,configuration, arrangement, and/or components that enable the flexiblesubstrate coating apparatus 600 to deposit a lithium anode deviceaccording to implementations of the present disclosure. For example, butnot limited to, the processing chambers may include suitable depositionsystems including coating sources, power sources, individual pressurecontrols, deposition control systems, and temperature control. Accordingto typical implementations, the chambers are provided with individualgas supplies. The chambers are typically separated from each other forproviding a good gas separation. The flexible substrate coatingapparatus 600 according to implementations described herein is notlimited in the number of deposition chambers. For example, but notlimited to, flexible substrate coating apparatus 600 may include 3, 6,or 12 processing chambers.

The processing chambers 610-640 typically include one or more depositionunits 612, 622, 632, and 642. Generally, the one or more depositionunits as described herein can be selected from a CVD source, a PECVDsource and a PVD source. The one or more deposition units can include anevaporation source (thermal evaporation or e-beam), a sputter source,such as, a magnetron sputter source, DC sputter source, AC sputtersource, pulsed sputter source, radio frequency (RF) sputtering, ormiddle frequency (MF) sputtering can be provided. For instance, MFsputtering with frequencies in the range of 5 kHz to 100 kHz, forexample, 30 kHz to 50 kHz, can be provided. The one or more depositionunits can include an evaporation source. In one implementation, theevaporation source is a thermal evaporation source or an electron beamevaporation. In one implementation, the evaporation source is a lithium(Li) source. Further, the evaporation source may also be an alloy of twoor more metals. The material to be deposited (e.g., lithium) can beprovided in a crucible. The lithium can, for example, be evaporated bythermal evaporation techniques or by electron beam evaporationtechniques.

In some implementations, any of the processing chambers 610-640 of theflexible substrate coating apparatus 600 may be configured forperforming deposition by sputtering, such as magnetron sputtering. Asused herein, “magnetron sputtering” refers to sputtering performed usinga magnet assembly, that is, a unit capable of a generating a magneticfield. Typically, such a magnet assembly includes a permanent magnet.This permanent magnet is typically arranged within a rotatable target orcoupled to a planar target in a manner such that the free electrons aretrapped within the generated magnetic field generated below therotatable target surface. Such a magnet assembly may also be arrangedcoupled to a planar cathode.

Magnetron sputtering may also be realized by a double magnetron cathode,such as, but not limited to, a TwinMag™ cathode assembly. In someimplementations, the cathodes in the processing chamber may beinterchangeable. Thus, a modular design of the apparatus is providedwhich facilitates optimizing the apparatus for particular manufacturingprocesses. In some implementations, the number of cathodes in a chamberfor sputtering deposition is chosen for optimizing an optimalproductivity of the flexible substrate coating apparatus 600.

In some implementations, one or some of the processing chambers 610-640may be configured for performing sputtering without a magnetronassembly. In some implementations, one or some of the chambers may beconfigured for performing deposition by other methods, such as, but notlimited to, chemical vapor deposition, atomic laser deposition or pulsedlaser deposition. In some implementations, one or some of the chambersmay be configured for performing a plasma treatment process, such as aplasma oxidation or plasma nitridation process.

In some implementations, the processing chambers 610-640 are configuredto process both sides of the continuous sheet of material 650. Althoughthe flexible substrate coating apparatus 600 is configured to processthe continuous sheet of material 650, which is horizontally oriented,the flexible substrate coating apparatus 600 may be configured toprocess substrates positioned in different orientations, for example,the continuous sheet of material 650 may be vertically oriented. In someimplementations, the continuous sheet of material 650 is a flexibleconductive substrate. In some implementations, the continuous sheet ofmaterial 650 includes a conductive substrate with one or more layersformed thereon. In some implementations, the conductive substrate is acopper substrate.

In some implementations, the flexible substrate coating apparatus 600comprises a transfer mechanism 652. The transfer mechanism 652 maycomprise any transfer mechanism capable of moving the continuous sheetof material 650 through the processing region of the processing chambers610-640. The transfer mechanism 652 may comprise a common transportarchitecture. The common transport architecture may comprise areel-to-reel system with a common take-up reel 654 positioned in thewinding module 606, the coating drum 655 positioned in the processingmodule 604, and a feed reel 656 positioned in the unwinding module 602.The take-up reel 654, the coating drum 655, and the feed reel 656 may beindividually heated. The take-up reel 654, the coating drum 655 and thefeed reel 656 may be individually heated using an internal heat sourcepositioned within each reel or an external heat source. The commontransport architecture may further comprise one or more auxiliarytransfer reels 653 a, 653 b (collectively 653) positioned between thetake-up reel 654, the coating drum 655, and the feed reel 656. Althoughthe flexible substrate coating apparatus 600 is depicted as having asingle processing region, in some implementations, it may beadvantageous to have separated or discrete processing regions for eachindividual processing chamber 610-640. For implementations havingdiscrete processing regions, modules, or chambers, the common transportarchitecture may be a reel-to-reel system where each chamber orprocessing region has an individual take-up-reel and feed reel and oneor more optional intermediate transfer reels positioned between thetake-up reel and the feed reel.

The flexible substrate coating apparatus 600 may comprise the feed reel656 and the take-up reel 654 for moving the continuous sheet of material650 through the different processing chambers 610-640. In oneimplementation, the first processing chamber 610 and the secondprocessing chamber 620 are each configured to deposit a portion of alithium metal film. The third processing chamber 630 is configured todeposit a chalcogenide film. The fourth processing chamber 640 isconfigured to deposit a lithium fluoride film over the chalcogenidefilm. In another implementation, the first processing chamber 610 andthe second processing chamber 620 are each configured to deposit aportion of a lithium metal film. The third processing chamber 630 isconfigured to deposit a dielectric film. The fourth processing chamber640 is configured to deposit a lithium fluoride film over the dielectricfilm. In yet another implementation, the first processing chamber 610and the second processing chamber 620 are each configured to deposit aportion of a lithium metal film. The third processing chamber 630 isconfigured to deposit a chalcogenide film. The fourth processing chamber640 is configured to deposit a metallic film over the chalcogenide film.In yet another implementation, the first processing chamber 610 and thesecond processing chamber 620 are each configured to deposit a portionof a lithium metal film. The third processing chamber 630 is configuredto deposit a metallic film over the lithium metallic film. The fourthprocessing chamber 640 is configured to deposit a lithium fluoride filmover the metallic film.

In one implementation, processing chambers 610-620 are configured fordepositing a thin film of lithium metal on the continuous sheet ofmaterial 650. Any suitable lithium deposition process for depositingthin films of lithium metal may be used to deposit the thin film oflithium metal. Deposition of the thin film of lithium metal may be byPVD processes, such as evaporation (e.g., thermal evaporation ore-beam), a slot-die process, a transfer process, a lamination process ora three-dimensional lithium printing process. The chambers fordepositing the thin film of lithium metal may include a PVD system, suchas a thermal evaporator, an electron-beam evaporator, a thin filmtransfer system (including large area pattern printing systems such asgravure printing systems), a lamination system, or a slot-die depositionsystem.

In one implementation, the third processing chamber 630 is configuredfor depositing a chalcogenide film on the lithium metal film. Thechalcogenide film may be deposited using a PVD sputtering technique asdescribed herein. In one implementation, the fourth processing chamber640 is configured for forming a lithium fluoride film on thechalcogenide film. Any suitable lithium deposition process fordepositing thin films of lithium metal may be used to deposit the thinfilm of lithium metal. Deposition of the thin film of lithium metal maybe by PVD processes, such as evaporation, a slot-die process, a transferprocess, a lamination process or a three-dimensional lithium printingprocess. In one implementation, the fourth processing chamber 640 is anevaporation chamber or PVD chamber configured to deposit a lithiumfluoride film over the continuous sheet of material 650. In oneimplementation, the evaporation chamber has a processing region that isshown to comprise an evaporation source that may be placed in acrucible, which may be a thermal evaporator or an electron beamevaporator (cold) in a vacuum environment, for example.

In operation, the continuous sheet of material 650 is unwound from thefeed reel 656 as indicated by the substrate movement direction shown byarrow 608. The continuous sheet of material 650 may be guided via one ormore auxiliary transfer reels 653 a, 653 b. It is also possible that thecontinuous sheet of material 650 is guided by one or more substrateguide control units (not shown) that shall control the proper run of theflexible substrate, for instance, by fine adjusting the orientation ofthe flexible substrate.

After uncoiling from the feed reel 656 and running over the auxiliarytransfer reel 653 a, the continuous sheet of material 650 is then movedthrough the deposition areas provided at the coating drum 655 andcorresponding to positions of the deposition units 612, 622, 632, and642. During operation, the coating drum 655 rotates around axis 651 suchthat the flexible substrate moves in the direction of arrow 608.

Implementations:

Clause 1. A method, comprising forming a lithium metal film on a currentcollector, wherein the current collector comprises copper and/orstainless steel; and forming a protective film stack on the lithiummetal film, comprising forming a first protective film on the lithiummetal film, wherein the first protective film is selected from a bismuthchalcogenide film, a copper chalcogenide film, a tin chalcogenide film,a gallium chalcogenide film, a germanium chalcogenide film, an indiumchalcogenide film, a silver chalcogenide film, a dielectric film, alithium fluoride film, or a combination thereof.

Clause 2. The method of clause 1, wherein forming the protective filmstack further comprises forming a second protective film on the firstprotective film, the second protective film selected from a lithiumfluoride (LiF) film, a metallic film, a carbon-containing film, or acombination thereof.

Clause 3. The method of clause 1 or 2, wherein the dielectric film isselected from oxides of: titanium (Ti), aluminum (Al), niobium (Nb),tantalum (Ta), zirconium (Zr), or a combination thereof.

Clause 4. The method of any clauses 1 to 3, wherein the bismuthchalcogenide film and the copper chalcogenide film are selected fromCuS, Cu₂Se, Cu₂S, Cu₂Te, CuTe, Bi₂Te₃, Bi₂Se₃, or a combination thereof.

Clause 5. The method of any of clauses 2 to 4, wherein the metallic filmis selected from tin (Sn), antimony (Sb), bismuth (Bi), gallium (Ga),germanium (Ge), copper (Cu), silver (Ag), gold (Au), or a combinationthereof.

Clause 6. The method of any of clauses 1 to 5, wherein the firstprotective film is the bismuth chalcogenide film or the copperchalcogenide film and the second protective film is lithium fluoride.

Clause 7. The method of any of clauses 1 to 6, wherein the firstprotective film is the bismuth chalcogenide film or the copperchalcogenide film and the second protective film is the metallic film.

Clause 8. The method of any of clauses 2 to 7, wherein the firstprotective film is the lithium fluoride film and the second protectivefilm is the carbon-containing film.

Clause 9. The method of any clauses 1 to 8, wherein the first protectivefilm has a thickness of 100 nanometers or less.

Clause 10. The method of any clauses 1 to 9, further comprising exposingthe current collector to a plasma treatment or corona discharge processto remove organic materials from exposed surfaces of the currentcollector prior to forming the lithium metal film on the currentcollector.

Clause 11. The method of any clauses 1 to 10, wherein forming the firstprotective film comprises performing at least one of a sputteringprocess, a thermal evaporation process, an e-beam evaporation process,and a chemical vapor deposition (CVD) process.

Clause 12. The method of claim any clauses 2 to 11, wherein forming thesecond protective film comprises performing at least one of a sputteringprocess, a thermal evaporation process, an e-beam evaporation process,and a chemical vapor deposition (CVD) process.

Clause 13. The method of any clauses 2 to 12, wherein the secondprotective film has a thickness of 100 nanometers or less.

Clause 14. An anode electrode structure, comprising a current collectorcomprising copper and/or stainless steel; a lithium metal film formed onthe current collector; and a protective film stack formed on the lithiummetal film, comprising a first protective film formed on the lithiummetal film, wherein the first protective film is selected from a bismuthchalcogenide film, a copper chalcogenide film, a tin chalcogenide film,a gallium chalcogenide film, a germanium chalcogenide film, an indiumchalcogenide film, a silver chalcogenide film, a dielectric film, alithium fluoride film, or a combination thereof; and a second protectivefilm formed on the first protective film, the second protective filmselected from a lithium fluoride (LiF) film, a metallic film, acarbon-containing film, or a combination thereof.

Clause 15. The anode electrode structure of clause 14, wherein thedielectric film is selected from oxides of: titanium (Ti), aluminum(Al), niobium (Nb), tantalum (Ta), zirconium (Zr), or a combinationthereof.

Clause 16. The anode electrode structure of clause 14 or 15, wherein thebismuth chalcogenide film and the copper chalcogenide film are selectedfrom CuS, Cu₂Se, Cu₂S, Cu₂Te, CuTe, Bi₂Te₃, Bi₂Se₃, or a combinationthereof.

Clause 17. The anode electrode structure of any of clauses 14 to 16,wherein the metallic film is selected from tin (Sn), antimony (Sb),bismuth (Bi), gallium (Ga), germanium (Ge), copper (Cu), silver (Ag),gold (Au), or a combination thereof.

Clause 18. The anode electrode structure of any of clauses 14 to 17,wherein the first protective film is the bismuth chalcogenide film orthe copper chalcogenide film and the second protective film is lithiumfluoride.

Clause 19. The anode electrode structure of any of clauses 14 to 18,wherein the first protective film is the bismuth chalcogenide film orthe copper chalcogenide film and the second protective film is themetallic film.

Clause 20. The anode electrode structure of any of clauses 14 to 19,wherein the first protective film is the lithium fluoride film and thesecond protective film is the carbon-containing film.

Clause 21. The anode electrode structure of any of clauses 14 to 20,wherein the first protective film has a thickness of 100 nanometers orless.

Clause 22. The anode electrode structure of any of clauses 14 to 21,wherein the second protective film has a thickness of 100 nanometers orless.

Clause 23. An energy storage device, comprising the anode electrodestructure of any of clauses claims 14 to 22; a cathode electrodestructure; and a solid electrolyte film formed between the anodeelectrode structure and the cathode electrode structure.

Clause 24. The energy storage device of clause 23, wherein the solidelectrolyte film is comprised of one or more of: LiPON, doped variantsof either crystalline or amorphous phases of Li₇La₃Zr₂O₁₂, dopedanti-perovskite compositions, argyrodite compositions,lithium-sulfur-phosphorous materials, Li₂S—P₂S₅, Li₁₀GeP₂S₁₂, andLi₃PS₄, lithium phosphate glasses, (1-x)LiI-(x)Li₄SnS₄,xLiI-(1-x)Li₄SnS₄, mixed sulfide and oxide electrolytes (crystallineLLZO, amorphous (1-x)LiI-(x)Li₄SnS₄ mixture, amorphousxLiI-(1-x)Li₄SnS₄), Li₃S(BF₄)_(0.5)Cl_(0.5), Li₄Ti₅O₁₂, lithium dopedlanthanum titanate (LATP), Li_(2+2x)Zn_(1-x)GeO₄, LiTi₂(PO₄)₃,LiHf₂(PO₄)₃, LiGe₂(PO₄)₃, and a combination thereof.

In summary, some of the benefits of the present disclosure include theefficient integration of lithium metal deposition into currentlyavailable processing systems. Currently, lithium metal deposition isperformed in a dry room or an argon gas atmosphere. Due to thevolatility of lithium metal, subsequent processing operations areperformed in an argon gas atmosphere. Performance of subsequentprocessing operations in an argon gas atmosphere would involveretrofitting of current manufacturing tools. It has been found by theinventors that coating the lithium metal with a protective film prior tosubsequent processing, allows subsequent processing to be performedeither under vacuum or in atmosphere. The protective film eliminates theneed to perform additional processing operations in an inert gasatmosphere reducing the complexity of tools. The protective film alsoallows for the transportation, storage, or both of the negativeelectrode with the lithium metal film formed thereon. In addition, inimplementations where the protective film is an ion-conducting film, theion-conducting film can be incorporated into the final battery structurereducing the complexity of the battery formation process. This reducesthe complexity of the tool and subsequently reduces the cost ofownership.

When introducing elements of the present disclosure or exemplary aspectsor implementation(s) thereof, the articles “a,” “an,” “the” and “said”are intended to mean that there are one or more of the elements.

The terms “comprising,” “including” and “having” are intended to beinclusive and mean that there may be additional elements other than thelisted elements.

While the foregoing is directed to implementations of the presentdisclosure, other and further implementations of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

1. A method of fabricating a lithium-containing electrode, the methodcomprising: forming a lithium metal film on a current collector, thecurrent collector comprising copper, stainless steel, or combinationsthereof; and forming a protective film stack on the lithium metal film,the protective film stack comprising: forming a first protective film onthe lithium metal film, the first protective film comprising bismuth,silver, tin, a bismuth chalcogenide, a tin chalcogenide, a silverchalcogenide, or combinations thereof; and forming a second protectivefilm on the first protective film, the second protective film comprisingLiF, an aluminum oxide, an aluminum oxyhydroxide (AlO(OH)), orcombinations thereof.
 2. The method of claim 1, wherein the secondprotective film comprises the LiF.
 3. The method of claim 2, wherein thefirst protective film is selected from the group consisting of bismuth,silver, tin, and combinations thereof.
 4. The method of claim 1, whereinthe second protective film is selected from the group consisting ofaluminum oxide, aluminum oxyhydroxide, and combinations thereof.
 5. Themethod of claim 1, wherein the first protective film has a thickness of100 nanometers or less.
 6. The method of claim 1, further comprisingexposing the current collector to a plasma treatment or corona dischargeprocess to remove organic materials from exposed surfaces of the currentcollector prior to forming the lithium metal film on the currentcollector.
 7. The method of claim 1, wherein forming the firstprotective film comprises performing at least one of a sputteringprocess, a thermal evaporation process, an e-beam evaporation process,and a chemical vapor deposition (CVD) process.
 8. The method of claim 1,wherein forming the second protective film comprises performing at leastone of a sputtering process, a thermal evaporation process, an e-beamevaporation process, and a chemical vapor deposition (CVD) process. 9.An anode electrode structure, comprising: a current collector comprisingcopper, stainless steel, or combinations thereof; a lithium metal filmformed on the current collector; and a protective film stack formed onthe lithium metal film, the protective film stack comprising: a firstprotective film on the lithium metal film, the first protective filmcomprising bismuth, silver, tin, a bismuth chalcogenide, a tinchalcogenide, a silver chalcogenide, or combinations thereof; and asecond protective film on the first protective film, the secondprotective film comprising LiF, an aluminum oxide, an aluminumoxyhydroxide (AlO(OH)), or combinations thereof.
 10. The anode electrodestructure of claim 9, wherein the second protective film comprises theLiF.
 11. The anode electrode structure of claim 10, wherein the firstprotective film is selected from the group consisting of bismuth,silver, tin, and combinations thereof.
 12. The anode electrode structureof claim 9, wherein the second protective film is selected from thegroup consisting of aluminum oxide, aluminum oxyhydroxide, andcombinations thereof.
 13. The anode electrode structure of claim 12,wherein, when the second protective film is selected from the groupconsisting of aluminum oxide, aluminum oxyhydroxide, and combinationsthereof, the first protective film is selected from the group consistingof bismuth, silver, tin, and combinations thereof.
 14. The anodeelectrode structure of claim 9, wherein the first protective film has athickness of 100 nanometers or less.
 15. An energy storage device,comprising: the anode electrode structure of claim 9; a cathodeelectrode structure; and a solid electrolyte film formed between theanode electrode structure and the cathode electrode structure.
 16. Theenergy storage device of claim 15, wherein the solid electrolyte film iscomprised of LiPON, doped variants of either crystalline or amorphousphases of Li₇La₃Zr₂O₁₂, doped anti-perovskite compositions, argyroditecompositions, lithium-sulfur-phosphorous materials, Li₂S—P₂S₅,Li₁₀GeP₂S₁₂, and Li₃PS₄, lithium phosphate glasses, (1-x)LiI-(x)Li₄SnS₄,xLiI-(1-x)Li₄SnS₄, mixed sulfide and oxide electrolytes (crystallineLLZO, amorphous (1-x)LiI-(x)Li₄SnS₄ mixture, amorphousxLiI-(1-x)Li₄SnS₄), Li₃S(BF₄)_(0.5)Cl_(0.5), Li₄Ti₅O₁₂, lithium dopedlanthanum titanate (LATP), Li_(2+2x)Zn_(1-x)GeO₄, LiTi₂(PO₄)₃,LiHf₂(PO₄)₃, LiGe₂(PO₄)₃, or combinations thereof.
 17. An anodeelectrode structure, comprising: a current collector comprising copper,stainless steel, or combinations thereof; a lithium metal film formed onthe current collector; and a protective film stack formed on the lithiummetal film, the protective film stack comprising: a first protectivefilm on the lithium metal film, the first protective film comprisingbismuth, silver, tin, a bismuth chalcogenide, a tin chalcogenide, asilver chalcogenide, or combinations thereof, the first protective filmhaving a thickness of 100 nanometers or less; and a second protectivefilm on the first protective film, the second protective film comprisingLiF, an aluminum oxide, an aluminum oxyhydroxide (AlO(OH)), orcombinations thereof.
 18. The anode electrode structure of claim 17,wherein the second protective film comprises the LiF.
 19. The anodeelectrode structure of claim 18, wherein the first protective filmcomprises the bismuth, silver, tin, or combinations thereof.
 20. Theanode electrode structure of claim 17, wherein the second protectivefilm comprises the aluminum oxide, aluminum oxyhydroxide, orcombinations thereof.